Author: Matthew Stephen Fox Publisher: ISBN: Category : Languages : en Pages : 286
Book Description
Imaging of the lungs using non-ionizing approaches such as hyperpolarized 3He and 129Xe magnetic resonance imaging (MRI) is a useful tool both for research and clinical applications. This work focused on development of 129Xe MRI techniques to investigate inflammation in rat lungs. A rodent model of inflammation, specifically radiationinduced lung injury (RILI) was developed using a collimated 60Co source. A quantitative MRI technique measuring absolute ventilated lung volume (values obtained from rats using the previously established 3He method and those obtained with 129Xe, the usefulness of 129Xe for future investigations of.
Author: Hans-Ulrich Kauczor Publisher: Springer Science & Business Media ISBN: 3540346198 Category : Medical Languages : en Pages : 315
Book Description
During the past decade significant developments have been achieved in the field of magnetic resonance imaging (MRI), enabling MRI to enter the clinical arena of chest imaging. Standard protocols can now be implemented on up-to-date scanners, allowing MRI to be used as a first-line imaging modality for various lung diseases, including cystic fibrosis, pulmonary hypertension and even lung cancer. The diagnostic benefits stem from the ability of MRI to visualize changes in lung structure while simultaneously imaging different aspects of lung function, such as perfusion, respiratory motion, ventilation and gas exchange. On this basis, novel quantitative surrogates for lung function can be obtained. This book provides a comprehensive overview of how to use MRI for imaging of lung disease. Special emphasis is placed on benign diseases requiring regular monitoring, given that it is patients with these diseases who derive the greatest benefit from the avoidance of ionizing radiation.
Author: Sarmad Siddiqui Publisher: ISBN: Category : Languages : en Pages : 378
Book Description
Lung transplantation is the established treatment for patients with chronic, end-stage lung diseases such as chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF) and cystic fibrosis (CF). However, its utility remains limited by the chronic shortage of donor lungs, limited lung preservation strategies and post-transplant complications leading to graft failure. Although efforts have been made to expand the limited pool of viable donor lungs via novel preservation strategies such as ex vivo lung perfusion (EVLP), our limited understanding of the mechanism and progression of donor lung injury continues to inhibit our ability to fully exploit these advances to improve lung transplant outcomes. Furthermore, the clinical standard for post-transplant assessment is limited to whole lung measurement such as pulmonary functional tests (PFTs) and structural imaging via radiography or HRCT, both of which lack the necessary sensitivity to detect lung rejection early. Given these limitations of currently available pre- and post-transplant lung assessment tools, a novel metabolic biomarker may provide higher sensitivity for determining the viability of donated lungs, as well as for assessing the onset of rejection before permanent structural changes in the lungs become apparent. We proposed that hyperpolarized (HP) [1-13C]pyruvate magnetic resonance imaging (MRI)--which provides real-time metabolic assessment of tissue based on the conversion of [1-13C] pyruvate to [1-13C]lactate via glycolysis, or to 13C bicarbonate via oxidative phosphorylation--may be an effective tool for assessing the health of donated lungs and may also serve as an early biomarker for detecting pulmonary graft dysfunction (PGD)-associated inflammation or acute lung rejection. In a rat model, we demonstrated the feasibility of using HP [1-13C]pyruvate nuclear magnetic resonance (NMR) spectroscopy to assess the viability of ex vivo perfused lungs. We further showed that our technique can be used to measure the improved viability of those lungs after treatment with ascorbic acid. Finally, translating our previously developed technique to in vivo HP [1-13C]pyruvate imaging of an inflamed rat lung, we not only demonstrated its utility for detecting lung transplantation rejection, but found that the HP lactate-to-pyruvate ratio is a better predictor of acute lung rejection in a rat model than computed tomography.
Author: Robert P. Thomen Publisher: ISBN: Category : Electronic dissertations Languages : en Pages : 197
Book Description
Magnetic Resonance Imaging (MRI) is an application of the nuclear magnetic resonance (NMR) phenomenon to non-invasively generate 3D tomographic images. MRI is an emerging modality for the lung, but it suffers from low sensitivity due to inherent low tissue density and short T2*. Hyperpolarization is a process by which the nuclear contribution to NMR signal is greatly enhanced to more than 100,000 times that of samples in thermal equilibrium. The noble gases 3He and 129Xe are most often hyperpolarized by transfer of light angular momentum through the electron of a vaporized alkali metal to the noble gas nucleus (called Spin Exchange Optical Pumping). The enhancement in NMR signal is so great that the gas itself can be imaged via MRI, and because noble gases are chemically inert, they can be safely inhaled by a subject, and the gas distribution within the interior of the lung can be imaged. The mechanics of respiration is an elegant physical process by which air is is brought into the distal airspaces of the lungs for oxygen/carbon dioxide gas exchange with blood. Therefore proper description of lung function is intricately related to its physical structure, and the basic mechanical operation of healthy lungs -- from pressure driven airflow, to alveolar airspace gas kinetics, to gas exchange by blood/gas concentration gradients, to elastic contraction of parenchymal tissue -- is a process decidedly governed by the laws of physics. This dissertation will describe experiments investigating the relationship of lung structure and function using hyperpolarized (HP) noble gas MRI. In particular HP gases will be applied to the study of several pulmonary diseases each of which demonstrates unique structure-function abnormalities: asthma, cystic fibrosis, and chronic obstructive pulmonary disease. Successful implementation of an HP gas acquisition protocol for pulmonary studies is an involved and stratified undertaking which requires a solid theoretical foundation in NMR and hyperpolarization theory, construction of dedicated hardware, development of dedicated software, and appropriate image analysis techniques for all acquired data. The author has been actively involved in each of these and has dedicated specific chapters of this dissertation to their description. First, a brief description of lung structure-function investigations and pulmonary imaging will be given (chapter 1). Brief discussions of basic NMR, MRI, and hyperpolarization theory will be given (chapters 2 and 3) followed by their particular methods of implementation in this work (chapters 4 and 5). Analysis of acquired HP gas images will be discussed (chapter 6), and the investigational procedures and results for each lung disease examined will be detailed (chapter 7). Finally, a quick digression on the strengths and limitations of HP gas MRI will be provided (chapter 8).
Author: Mitchell S. Albert Publisher: Academic Press ISBN: 0128037040 Category : Science Languages : en Pages : 334
Book Description
Hyperpolarized and Inert Gas MRI: Theory and Applications in Research and Medicine is the first comprehensive volume published on HP gas MRI. Since the 1990's, when HP gas MRI was invented by Dr. Albert and his colleagues, the HP gas MRI field has grown dramatically. The technique has proven to be a useful tool for diagnosis, disease staging, and therapy evaluation for obstructive lung diseases, including asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis. HP gas MRI has also been developed for functional imaging of the brain and is presently being developed for molecular imaging, including molecules associated with lung cancer, breast cancer, and Alzheimer's disease. Taking into account the ongoing growth of this field and the potential for future clinical applications, the book pulls together the most relevant and cutting-edge research available in HP gas MRI into one resource. - Presents the most comprehensive, relevant, and accurate information on HP gas MRI - Co-edited by the co-inventor of HP gas MRI, Dr. Albert, with chapter authors who are the leading experts in their respective sub-disciplines - Serves as a foundation of understanding of HP gas MRI for researchers and clinicians involved in research, technology development, and clinical use with HP gas MRI - Covers all hyperpolarized gases, including helium, the gas with which the majority of HP gas MRI has been conducted
Author: Peder Larson Publisher: Elsevier ISBN: 0128222697 Category : Psychology Languages : en Pages : 296
Book Description
MRI with hyperpolarized carbon-13 agents is a powerful emerging imaging modality that can measure real-time metabolism in cells, animals, and humans. It uses endogenous, non-toxic contrast agents that a hyperpolarized, resulting in up to 100,000-fold increases in sensitivity. This technique uses no ionizing radiation, and is being applied in a range of human trials. It's primary use is for metabolic imaging, but it can also measure perfusion, pH, and necrosis. Hyperpolarized Carbon-13 Magnetic Resonance Imaging and Spectroscopy is designed to be a one stop shop for understanding hyperpolarized 13C MRI. This book explains the principles of this imaging modality, the requirements for performing studies, shows how to interpret the results, and gives an overview of current biomedical applications. It is suitable for engineers, scientists and clinicians in radiology and biomedical imaging who want to understand this technology. Presents the physics and hardware of dissolution dynamic nuclear polarization Explains the behaviour of hyperpolarized carbon-13 agents and how to image them Detailed guidance on experimental design and data interpretation Identifies promising and potential applications of hyperpolarized carbon-13 MR
Author: François-Xavier Blé Publisher: ISBN: Category : Languages : en Pages : 266
Book Description
Magnetic resonance imaging (MRI) is able to detect water content in the biological tissue and thus to non-invasively assess on a regional basis infiltrated water and/or secreted fluids and/or tissue densification. In pulmonary diseases such as asthma, chronic obstructive pulmonary diseases or fibrosis, plasma exudation, mucus secretion and thickening of the lung tissue constitute hallmarks of the pathological status that directly contribute to functional impairment. These features are well conserved in experimental pulmonary disease models in the small rodents. A particular interest is given to murine models that have provided, in parallel to the technological progress in genetic engineering and molecular biology, a reliable in vivo support for lung disease understanding and investigation. Nowadays, routine methods used to evaluate disease state of the lung in these models are either terminal or gives functional estimation of the global airways.Therefore, we have set up a method using MRI technique to non-invasively depict different hallmarks occurring in a murine model of asthma. In this thesis, we have demonstrated that proton MRI provides a relevant mean to assess and follow signals associated with the plasma leakage and mucus secretions in the lung, which are both important features of the inflammatory response following allergenic provocation. To further confirm these findings, we have also validated in this model the effect of pharmacological tools. We chose to study sphingosine-1-phosphate (S1P) pharmacology on the basis of recent publications indicating a possible implication of this endogenous mediator in inflammation and lung barrier integrity in models of asthma. In two studies examining the effects of the general S1P agonist FTY720 and of the S1P2 antagonist JTE013, the incidence of plasma leakage on fluid signal detection was highlighted in our murine model of airway inflammation and confirmed by histology and BAL fluid analyses. Additionally, since the technique had been previously set up in the rat, we extended the knowledge in this species. In this regard, we achieved the selective detection and monitoring of mucus dynamics by MRI with the use of a specific contrast agent in a model of endotoxin-induced mucus hypersecretion. Besides, we also demonstrated the capabilities of MRI to follow the hydration of airway secretions. In this non-inflammatory model, the formation of MRI fluid signals were induced by hypertonic saline instillation and dose-dependently enhanced by different compounds that interact directly or indirectly with epithelial Na+ channel (ENaC), a major regulator of airway surface liquid hydration. These studies have been successfully performed in the rat with the perspective of future translation to murine models for transgenic application. Finally, we have partially validated the application of this technique to a less acute model, the murine bleomycin-induced fibrosis. This model has been chosen regarding its admitted relevance to mimic global characteristics of human pulmonary fibrosis in addition to its simplicity to be set up. In this study, we have been able to follow by MRI the course of edematous, mucous and/or fibrotic features in correlation with histological findings. In summary, the present work is bringing evidence of possible contributions of MRI in pulmonary disease investigations in mouse and rat, and postulates for its use to complete and/or replace the methods used nowadays to evaluate experimental murine models.
Author: Matthew Stephen Fox
Author: Hans-Ulrich Kauczor
Author: Sarmad Siddiqui
Author: D. M. L. Lilburn
Author: David M. L. Lilburn
Author: Robert P. Thomen
Author: Mitchell S. Albert
Author: Peder Larson
Author: Adelaide Zhang
Author: François-Xavier Blé